Semiconductor manufacturing apparatus and manufacturing method of semiconductor device

ABSTRACT

A semiconductor manufacturing apparatus according to the present embodiment comprises a chamber. A chemical-agent supply part is configured to supply a water-repellent agent or an organic solvent to a surface of a semiconductor substrate having been cleaned with a cleaning liquid in the chamber. A spray part is configured to spray a water-capture agent capturing water into an atmosphere in the chamber.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2013-011850, filed on Jan. 25,2013, the entire contents of which are incorporated herein by reference.

FIELD

The embodiments of the present invention relate to a semiconductormanufacturing apparatus and a manufacturing method of a semiconductordevice.

BACKGROUND

Semiconductor device manufacturing processes include various processessuch as a lithographic process, an etching process, and an ionimplantation process. After the end of each process and before shiftingto the next process, a cleaning process and a drying process areperformed so as to remove impurities and residues remaining on thesurface of a semiconductor substrate to clean the surface of thesemiconductor substrate.

In recent years, following the downscaling of elements, the aspect ratioof patterns on a semiconductor substrate has become higher. At a higheraspect ratio, there occurs a problem that capillary (surface tension)causes collapsing of the patterns on the semiconductor substrate in thedrying process.

To deal with such a problem, generally, there has been proposed to useIsopropyl alcohol (IPA), which is an organic solvent in the wet cleaningprocess. In a case of using the IPA, the IPA displaces DIW (deionizedwater) on a semiconductor substrate W and the surface of thesemiconductor substrate is dried with the IPA (subjected to an IPAdrying treatment). However, when much water is contained in theatmosphere in a chamber, there is a probability that the IPA absorbs thewater at a time of the IPA drying treatment and that watermarks areformed on the surface of the semiconductor substrate when the surface isdried.

Furthermore, there has been proposed a technique for making the surfaceof the semiconductor substrate water repellent and lowering thecapillary that acts between the patterns and a chemical liquid or DIW.However, a water-repellent agent used for making the surface of thesemiconductor substrate water repellent is often deactivated afterreacting to the water. For example, it often occurs in a cleaning devicethat the water-repellent agent is deactivated after reacting to thewater in a chamber. If such deactivation of the water-repellent agentoccurs, the water-repellent agent is unable to make the surface of thesemiconductor substrate water repellent and to suppress collapsing ofthe patterns on the semiconductor substrate resulting from the capillary(surface tension).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a configuration of a surface treatmentapparatus 10 for a semiconductor substrate according to a firstembodiment;

FIG. 2 shows a contact angle θ of a liquid on patterns 4 on thesemiconductor substrate W;

FIGS. 3A to 3D are cross-sectional views showing a manufacturing methodof a NAND flash memory according to the first embodiment;

FIG. 4 is a flowchart showing the surface treatment method according tothe first embodiment;

FIG. 5 is a flowchart showing the surface treatment method according tothe second embodiment;

FIGS. 6A and 6B show an example of a configuration of a surfacetreatment apparatus 30 for semiconductor substrates according to a thirdembodiment; and

FIG. 7 is a flowchart showing a surface treatment method according tothe third embodiment.

DETAILED DESCRIPTION

Embodiments will now be explained with reference to the accompanyingdrawings. The present invention is not limited to the embodiments.

A semiconductor manufacturing apparatus according to the presentembodiment comprises a chamber. A chemical-agent supply part isconfigured to supply a water-repellent agent or an organic solvent to asurface of a semiconductor substrate having been cleaned with a cleaningliquid in the chamber. A spray part is configured to spray awater-capture agent capturing water into an atmosphere in the chamber.

First Embodiment

FIG. 1 shows an example of a configuration of a surface treatmentapparatus 10 for a semiconductor substrate according to a firstembodiment. The surface treatment apparatus 10 includes a mounting unit100 on which a semiconductor substrate (a wafer) W is mounted, a liquidsupply unit 200 that supplies liquids, a chamber 300 that hermeticallyseals the semiconductor substrate W, and a spray unit 400 that sprays awater-capture agent 2.

The mounting unit 100 includes a rotary shaft 102, a spin base 103, andchuck pins 104. The rotary shaft 102 extends substantially in a verticaldirection and the disk-like spin base 103 is attached on an upper end ofthe rotary shaft 102. A motor (not shown) can rotate the rotary shaft102 and the spin base 103.

The chuck pins 104 are provided on peripheral edges of the spin base103, respectively. The chuck pins 104 fix the semiconductor substrate Won the spin base 103 by putting the semiconductor substrate W betweenthe chuck pins 104. The mounting unit 100 can rotate the semiconductorsubstrate W while keeping the semiconductor substrate W substantiallyhorizontally.

The liquid supply unit 200 discharges a liquid 1 to a surface of thesemiconductor substrate W near a rotation center thereof. By allowingthe mounting unit 100 to rotate the semiconductor substrate W, thedischarged liquid 1 can spread in a radial direction of thesemiconductor substrate W and can be applied on the surface of thesemiconductor substrate W.

Furthermore, by allowing the mounting unit 100 to rotate thesemiconductor substrate W, the liquid 1 on the semiconductor substrate Wcan be drained off and the semiconductor substrate W can be spin-dried.The excessive liquid 1 spattering in the radial direction of thesemiconductor substrate W is discharged via a waste liquid pipe 105. Forexample, the liquid 1 is a cleaning liquid, a water-repellent agent, DIW(deionized water) or an organic solvent.

The liquid supply unit 200 includes a first chemical-liquid supply unit210 that supplies the cleaning liquid for cleaning the semiconductorsubstrate W to the surface of the semiconductor substrate W, a secondchemical-liquid supply unit 220 serving as a chemical-agent supply unitthat supplies the water-repellent agent for forming a water-repellentprotection film to the surface of the semiconductor substrate W, and aDIW supply unit 230 that supplies the DIW to the surface of thesemiconductor substrate W.

The cleaning liquid supplied from the first chemical-liquid supply unit210 passes through a supply pipe 212 and is discharged from a nozzle211. For example, the cleaning liquid is an SC1 liquid (Ammonia-HydrogenPeroxide mixture) or an SPM liquid (Sulfuric acid-Hydrogen PeroxideMixture) and is a chemical liquid used for removing etching residues andthe like.

The water-repellent agent supplied from the second chemical-liquidsupply unit 220 passes through a supply pipe 222 and is discharged froma nozzle 221. The water-repellent agent is a chemical liquid for formingthe water-repellent protection film on surfaces of patterns formed onthe semiconductor substrate W and making the surfaces of the patternswater repellent. For example, the water-repellent agent is a silanecoupling agent. The silane coupling agent contains hydrolytic groupshaving an affinity and a reactivity to inorganic materials and organicfunctional groups chemically bonding organic materials in molecules.Examples of the silane coupling agent include hexamethyldisilazane(HMDS), tetra methylsilyldimethyla mine (TMSDMA), andtrimethylsilyldimethylamine (TMSDEA).

The DIW supplied from the DIW supply unit 230 passes through a supplypipe 232 and is discharged from a nozzle 231. The DIW is used to rinseaway a chemical liquid on the semiconductor substrate W.

The spray unit 400 sprays the water-capture agent 2 into the chamber 300so as to capture water contained in an atmosphere in the chamber 300.Although not limited to a specific one, the water-capture agent 2suffices to be a chemical agent that easily reacts to the water and thatdoes not react to the chamber 300, the semiconductor substrate W, andthe water-repellent agent. For example, the silane coupling agentserving as the water-repellent agent can be used as the water-captureagent 2. Examples of the silane coupling agent include HMDS, TMSDMA, andTMSDEA mentioned above.

A material same as that of the water-repellent agent can be used as thatof the water-capture agent 2. However, when any one of HMDS, TMSDMA, andTMSDEA is used as the water-repellent agent, any of HMDS, TMSDMA, andTMSDEA can be used as the water-capture agent 2. In this case, adifferent material from that of the water-repellent agent can be used asthe material of the water-capture agent 2.

The spray unit 400 evaporates the water-repellent agent 2 and sprays theevaporated water-repellent agent 2 into the chamber 300. Thewater-repellent agent 2 thereby reacts to the water in the atmosphere inthe chamber 300 and captures the water. In other words, thewater-capture agent 2 absorbs the water in the chamber 300.

The spray unit 400 sprays the evaporated water-capture agent 2 into theatmosphere in the chamber 300 either simultaneously with or before atiming at which the second chemical-liquid supply unit 220 supplies thewater-repellent agent to the surface of the semiconductor substrate W.The spray unit 400 can continue spraying the water-repellent agent intothe chamber 300 in parallel to the supply of the water-repellent agentwhile the second chemical-liquid supply unit 220 is supplying thewater-repellent agent. The water-capture agent 2 can therebysufficiently capture the water in the chamber 300 before thewater-repellent agent is supplied to the semiconductor substrate W.Therefore, it is possible to suppress the water-repellent agent fromreacting to the water in the atmosphere in the chamber 300 and beingdeactivated. The spray unit 400 can spray the water-capture agent 2continuously, instantaneously or intermittently.

The surface treatment apparatus 10 can include a vacuum device (notshown) that evacuates the air from the interior of the chamber 300. Inthis case, the vacuum device discharges the water in the chamber 300 tooutside to some extent and the spray unit 400 sprays the water-repellentagent into the chamber 300 in a vacuum. It is thereby possible to removethe water in the chamber 300 more efficiently.

Furthermore, the surface treatment apparatus 10 can include an excimerUV (ultraviolet) irradiation unit (not shown). The excimer UVirradiation unit can selectively remove the water-repellent protectionfilm by irradiating UV light on the semiconductor substrate W.

FIG. 2 shows a contact angle θ of a liquid on patterns 4 on thesemiconductor substrate W. When an aspect ratio of the patterns 4becomes higher by downscaling the patterns 4, a liquid 5 enters betweenadjacent patterns 4 by the capillary of the liquid 5. In this case,power P with which the liquid 5 acts on the patterns 4 is represented bythe following Equation (1).

P=2×γ×cos θ·H/SPACE   (1)

In this equation, SPACE denotes a space between adjacent patterns 4. Hdenotes the height of each pattern 4. γ denotes the surface tension ofthe liquid 5.

It is understood that as the contact angle θ is closer to 90°, then cosθ becomes closer to zero and the power P acting on the patterns 4becomes lower. The fact that the contact angle θ is closer to 90° meansthat the surface of the semiconductor substrate W (the surface of eachpattern 4) is made water repellent. Therefore, pattern collapsing can besuppressed by making the surface of the semiconductor substrate W waterrepellent.

To make the surface of the semiconductor substrate W water repellent,the water-repellent protection film is formed on the surface of thesemiconductor substrate W using the water-repellent agent such as thesilane coupling agent (a sililation treatment). However, when the wateris present in the chamber 300, the silane coupling agent has ahydrolytic reaction to the water in the chamber 300 and loses awater-repellent function. That is, the silane coupling agent isdeactivated. For example, when the silane coupling agent is supplied tothe rotation center of the semiconductor substrate W shown in FIG. 1, itis likely that the silane coupling agent reacts to the water and isdeactivated before the silane coupling agent spreads through peripheraledges of the semiconductor substrate W. In this case, thewater-repellent protection film is formed on the patterns 4 near acentral portion of the semiconductor substrate W but not on the patterns4 near the peripheral edges of the semiconductor substrate W.

On the other hand, according to the first embodiment, the spray unit 400sprays the evaporated water-capture agent 2 into the chamber 300 at orbefore a time of supplying the water-repellent agent. Because thewater-capture agent 2 reacts to the water in the chamber 300, a wateramount in the chamber 300 greatly decreases at the time of supplying thewater-repellent agent. This can suppress deactivation of thewater-repellent agent. As a result, it is possible to ensure making thesurface of the semiconductor substrate W and the surfaces of thepatterns 4 water repellent, to make the contact angle θ closer to 90°,and to suppress collapsing of the patterns 4 on the semiconductorsubstrate W.

FIGS. 3A to 3D are cross-sectional views showing a manufacturing methodof a NAND flash memory according to the first embodiment. FIG. 4 is aflowchart showing a surface treatment method according to the firstembodiment.

The surface treatment method according to the first embodiment isapplied to, for example, processes of cleaning and drying thesemiconductor substrate W in processing of charge accumulation layers CA(floating gates, for example) of the NAND flash memory. Although asidewall transfer process is often used to process the chargeaccumulation layers CA, an ordinary resist transfer process is used herefor the brevity of descriptions. Needless to mention, the firstembodiment is also applicable to cleaning and drying processes in thesidewall transfer process.

First, a gate dielectric film 20 is formed on the semiconductorsubstrate W. The gate dielectric film 20 is formed by thermallyoxidizing the semiconductor substrate W. The thickness of the gatedielectric film 20 is about 5 nm, for example.

Next, a polysilicon layer 30 is formed on the gate dielectric film 20.The polysilicon layer 30 is used as the material of the chargeaccumulation layers CA. The thickness of the polysilicon layer 30 isabout 100 nm, for example.

Next, a silicon nitride film 40 is formed on the polysilicon layer 30.The silicon nitride film 40 functions as an etching stopper. Thethickness of the silicon nitride film 40 is about 100 nm, for example.

Next, a silicon oxide film 50 is formed on the silicon nitride film 40.The silicon oxide film 50 is used as hard masks HM for processing thepolysilicon layer 30 (the charge accumulation layers CA) or the like.The thickness of the silicon oxide film 50 is 250 nm, for example.

Next, a sacrificial film 60 is formed on the silicon oxide film 50. Itsuffices that the sacrificial film 60 is made of a material that canselectively etch the silicon oxide film 50. For example, a siliconnitride film, a polysilicon film or the like can be used as thesacrificial film 60. The thickness of the sacrificial film 60 is 100 nm,for example.

Next, using a lithographic technique, a resist layer 70 is formed on thesacrificial film 60. The resist layer 70 is patterned to process thesacrificial film 60 into patterns of the charge accumulation layers CA.For example, the resist layer 70 is formed into line-and-space patterns.The line width and space width of the resist layer 70 are both about 20nm, for example. The structure shown in FIG. 3A is obtained in thismanner.

Next, using the resist layer 70 as a mask, the sacrificial film 60 isprocessed by a RIE (Reactive Ion Etching) method.

After removing the resist layer 70 using, for example, a SPM liquid(Sulfuric acid-Hydrogen Peroxide Mixture), the silicon oxide film 50 isprocessed by the RIE method with the sacrificial film 60 used as a mask.Etching of the silicon oxide film 50 stops on the silicon nitride film40. The structure of the hard masks HM is thereby obtained as shown inFIG. 3B. At this time, an aspect ratio of each hard mask HM is about 10.The sacrificial film 60 can be removed at the time of etching thesilicon oxide film 50.

When the sidewall transfer process is used, the sacrificial film 60 isused as a core of sidewall masks (not shown). For example, afternarrowing the width of the sacrificial film 60 by slimming, a sidewallfilm (not shown) is deposited on the sacrificial film 60. Thereafter,the sidewall film is etched back, thereby leaving the sidewall film onboth side surfaces of the sacrificial film 60 as the sidewall masks. Thesidewall masks are formed by removing the sacrificial film 60. When thesilicon oxide film 50 is etched using the sidewall masks as a mask, itis possible to form the hard masks HM each having a smaller line widthand a smaller space width than those of a minimum feature size F(Feature size) that can be formed by the lithographic technique. In thisway, the hard masks HM can be alternatively processed using the sidewalltransfer process. Needless to mention, the hard masks HM can beprocessed into smaller patterns by repeating the sidewall transferprocess.

Next, the semiconductor substrate W is cleaned so as to remove etchingresidues generated in the etching of the silicon oxide film 50. Forexample, the semiconductor substrate W is subjected to a cleaningtreatment using the SPM liquid or the SC1 liquid.

After the cleaning treatment, the chemical liquid is rinsed away withthe DIW. At this time, the DIW enters between the adjacent hard masksHM. When the surface of the semiconductor substrate W is dried in astate where the DIW is present between the hard masks HM, the capillaryor surface tension (the power P represented by the Equation (1)mentioned above) of the DIW possibly causes collapsing of the hard masksHM.

To prevent this possibility, the surface treatment apparatus 10according to the first embodiment forms a water-repellent protectionfilm R on the surface of the semiconductor substrate W and those of thepatterns after the cleaning treatment. A method of forming thewater-repellent protection film R is described below with reference toFIG. 4.

FIG. 4 is a flowchart showing the surface treatment method according tothe first embodiment. As shown in FIG. 4, after mounting thesemiconductor substrate W on the mounting unit 10 (S10), the mountingunit 10 rotates the semiconductor substrate W. The first chemical-liquidsupply unit 210 supplies the cleaning liquid for cleaning thesemiconductor substrate W to the surface of the semiconductor substrateW arranged in the chamber 300. The cleaning liquid spreads throughoutthe surface of the semiconductor substrate W by rotation of thesemiconductor substrate W. The etching residues are thereby removed(S20: cleaning treatment). After cleaning the semiconductor substrate W,the DIW supply unit 230 supplies the DIW to the semiconductor substrateW. The DIW spreads throughout the surface of the semiconductor substrateW by the rotation of the semiconductor substrate W. The cleaning liquidon the surface of the semiconductor substrate W is thereby rinsed awaywith the DIW (S30: DIW rinse treatment).

Next, the spray unit 400 evaporates the water-capture agent 2 and spraysthe evaporated water-capture agent 2 into the chamber 300. Thewater-capture agent 2 thereby captures the water in the atmosphere inthe chamber 300 (S40: water capture treatment). For example, HMDSserving as the silane coupling agent can be used as the water-captureagent 2. In this case, HMDS reacts to the water and changes to silanol.Furthermore, the bimolecular silanol is condensed into inactivesiloxane. In this way, because the water-capture agent 2 reacts to thewater and changes to the inactive substance, the water in the chamber300 can be reduced.

Simultaneously with or after spraying of the water-capture agent 2, thesecond chemical-liquid supply unit 220 supplies the water-repellentagent to the surface of the semiconductor substrate W (S50: sililationtreatment). The water-repellent agent spreads throughout the surface ofthe semiconductor substrate W by the rotation of the semiconductorsubstrate W. For example, the water-repellent agent is TMSDMA serving asthe silane coupling agent. At this time, the water-repellent agent canspread throughout the surface of the semiconductor substrate W withoutbeing deactivated because the water is hardly present in the chamber300. The water-repellent protection film R is thereby formed on theentire surfaces of the patterns on the semiconductor substrate W.

When the patterns on the semiconductor substrate W are formed of asilicon-based film such as the silicon nitride film or the polysiliconfilm, sufficient water repellency is not often ensured because of aninsufficient sililation reaction even after the sililation treatmentusing the silane coupling agent. In this case, before Step S50, thesurfaces of the silicon-based patterns are changed to siliconoxide-based chemical oxide films using another chemical liquid. When thesililation treatment is subsequently performed, it is possible toimprove water repellency after the sililation treatment.

Many residues are generated after the etching by the RIE method. It isdifficult to form the water-repellent protection film in a state wheremany residues remain. Therefore, it is effective to remove the residuesby the cleaning treatment so as to form the water-repellent protectionfilm. In addition, plasma damages are accumulated on the surfaces of thepatterns by the RIE method and dangling bonds are generated. When areforming treatment is performed using a cleaning liquid having anoxidation effect, the dangling bonds terminate at OH groups. If many OHgroups are present, the sililation reaction probability increases, whichfacilitates forming the water-repellent protection film. This canfurther improve the water repellency. Even when the patterns are formedof the silicon oxide film, identical effects can be obtained. When thecleaning liquid has also a reforming effect (an oxidation effect), it ispossible to simultaneously perform the cleaning treatment and thereforming treatment using the single cleaning liquid.

Next, the DIW supply unit 230 supplies the DIW on the semiconductorsubstrate W and rinses again the surface of the semiconductor substrateW (S60: DIW rinse treatment). The DIW spreads throughout the surface ofthe semiconductor substrate W by the rotation of the semiconductorsubstrate W. The mounting unit 100 accelerates a rotational speed forrotating the semiconductor substrate W to a predetermined speed, therebydraining off and drying the DIW on the surface of the semiconductorsubstrate W (S70: spin drying treatment). At this time, the DIW can beeasily removed from the semiconductor substrate W because surfaces ofthe hard masks HM are already in a water repellent state. Furthermore,even if the DIW is present between the adjacent hard masks HM, thecapillary or surface tension of the DIW is very low because the surfacesof the hard masks HM are already in the water repellent state.Therefore, it is difficult for the hard masks HM to collapse.

Next, using the hard masks HM as a mask, the polysilicon layer 30, thegate dielectric film 20, and the semiconductor substrate W are processedby the RIE method. The structure shown in FIG. 3D is thereby obtained.

Thereafter, STI (Shallow Trench Isolation), IPD (Inter Poly Dielectric),control gates, and the like are formed using well-known processes,thereby completing the NAND flash memory.

As described above, according to the first embodiment, the water-captureagent 2 is sprayed into the atmosphere in the chamber 300 eithersimultaneously with or before the timing of supplying thewater-repellent agent to the surface of the semiconductor substrate W.The water-capture agent 2 thereby captures the water in the chamber 300before the water-repellent agent is supplied to the semiconductorsubstrate W. Therefore, it is possible to suppress the water-repellentagent from reacting to the water in the atmosphere in the chamber 300and being deactivated. As a result, according to the first embodiment,it is possible to ensure making the surface of the semiconductorsubstrate W water repellent and to suppress collapsing of the patternson the semiconductor substrate W.

Second Embodiment

The surface treatment apparatus 10 and a surface treatment methodaccording to a second embodiment differ from those according to thefirst embodiment in the use of an organic solvent in place of thewater-repellent agent. Therefore, the second chemical-liquid supply unit220 shown in FIG. 1 supplies not the water-repellent agent but theorganic solvent to the semiconductor substrate W. In this case, it isunnecessary to perform the DIW rinse treatment in Step S60 shown in FIG.4. Other configurations and processes of the second embodiment can beidentical to those of the first embodiment. Because configurations ofthe surface treatment apparatus according to the second embodiment arebasically identical to those of the surface treatment apparatus 10according to the first embodiment shown in FIG. 1, detailed explanationsthereof will be omitted.

In the second embodiment, the organic solvent is IPA, for example. Thewater-repellent agent can be used as the water-capture agent 2 similarlyto the water-capture agent 2 in the first embodiment. The organicsolvent is used in place of the water-repellent agent. This is becausemost of organic solvents have properties of low surface tension and highvolatility. Because of the low surface tension, it is possible tosuppress collapsing of the patterns on the semiconductor substrate W asdescribed above. Because of the high volatility, the drying treatmentcan be performed swiftly and easily. Therefore, the liquid supplied fromthe second chemical-liquid supply unit 220 suffices to be a liquid lowin surface tension without being specifically limited to the organicsolvent. The liquid having the high volatility as well as the lowsurface tension is preferable because the high volatility isadvantageous in the drying treatment.

The spray unit 400 sprays the water-capture agent 2 into the atmospherein the chamber 300 either simultaneously with or before a timing atwhich the second chemical-liquid supply unit 220 supplies the organicsolvent to the surface of the semiconductor substrate W. The spray unit400 can continue spraying the water-repellent agent 2 into the chamber300 in parallel to the supply of the organic solvent while the secondchemical-liquid supply unit 220 is supplying the organic solvent. Thewater-capture agent 2 can thereby capture the water in the chamber 300before the organic solvent is supplied to the semiconductor substrate W.Therefore, the organic solvent is suppressed from absorbing the water inthe atmosphere in the chamber 300 and the organic solvent displaces thewater present on the surfaces of the patterns on the semiconductorsubstrate W. The spray unit 400 can spray the water-capture agent 2continuously, instantaneously or intermittently.

FIG. 5 is a flowchart showing the surface treatment method according tothe second embodiment. Because Steps S10 to S40 in FIG. 5 are identicalto Steps S10 to S40 in FIG. 4, detailed explanations thereof will beomitted.

Simultaneously with or after spraying of the water-capture agent 2, thesecond chemical-liquid supply unit 220 supplies the organic solvent(IPA, for example) to the surface of the semiconductor substrate W(S51). At this time, the organic solvent spreads throughout the surfaceof the semiconductor substrate W without absorbing the water because thewater is hardly present in the chamber 300. The organic solvent therebydisplaces the water present on the surfaces of the patterns on thesemiconductor substrate W. Therefore, it is possible to suppresswatermarks from being formed on the surface of the semiconductorsubstrate W at the time of an IPA drying treatment.

Thereafter, the semiconductor substrate W is dried by the spin dryingtreatment. Step S70 shown in FIG. 5 is the same as Step S70 shown inFIG. 4.

Generally, when the IPA that is the organic solvent is used in thecleaning process, the IPA displaces the DIW on the semiconductorsubstrate W and dries the surface of the semiconductor substrate W (theIPA drying treatment). However, if much water is contained in theatmosphere in the chamber 300, there is a probability that the IPAabsorbs the water at the time of the IPD drying treatment and thatwatermarks are formed on the surface of the semiconductor substrate Wwhen the surface is dried.

According to the second embodiment, the water-capture agent 2 is sprayedinto the atmosphere in the chamber 300 either simultaneously with orbefore the timing of supplying the organic solvent to the surface of thesemiconductor substrate W. The water-capture agent 2 can thereby capturethe water in the chamber 300 before the organic solvent is supplied tothe semiconductor substrate W. Therefore, the organic solvent candisplace the water on the surface of the semiconductor substrate W andthose of the patterns without absorbing the water in the chamber 300. Ifthe IPA displaces the water on the surface of the semiconductorsubstrate W and those of the patterns, then wettability of the liquid 5on the surface of the semiconductor substrate W improves and cos θ inthe Equation (1) becomes larger, but γ in the Equation (1) becomessmaller. The power P thereby becomes lower as a whole. As a result, itis possible to suppress collapsing of the patterns on the semiconductorsubstrate W and to suppress the watermarks from being formed on thesemiconductor substrate W.

The first and second embodiments are not limited to the patterns of thehard masks HM described above but applicable to arbitrary patternshaving a high aspect ratio. Furthermore, the first and secondembodiments are not limited to the patterns of the hard masks HM in theprocess of cleaning the semiconductor substrate W but applicable toresist patterns after development in a lithographic process.

Furthermore, while the spray unit 400 shown in FIG. 1 can be arranged inan upper portion of the chamber 300 in the first embodiment, the sprayunit 400 can be formed integrally with the second chemical-liquid supplyunit 220. When the material of the water-capture agent 2 is the same asthat of the water-repellent agent, a common pipe to the spray unit 400and the second chemical-liquid supply unit 220 can be used by formingthe spray unit 400 and the second chemical-liquid supply unit 220integrally. This makes it relatively easier to pull out the pipe.

The first and second embodiments can be combined. In this case, thesurface treatment apparatus 10 includes both a water-repellent-agentsupply unit that supplies the water-repellent agent and an IPA supplyunit that supplies the IPA. For example, after cleaning thesemiconductor substrate W, the surface treatment apparatus 10 rinses thecleaning liquid with the DIW and supplies the IPA to the semiconductorsubstrate W by the method according to the second embodiment. The IPAthereby displaces the water on the semiconductor substrate W. Thesurface treatment apparatus 10 supplies the water-repellent agent to thesemiconductor substrate W by the method according to the firstembodiment. The water-repellent protection film is thereby formed on thesurface of the semiconductor substrate W (the surface of each pattern).The surface treatment apparatus 10 supplies the IPA again to thesemiconductor substrate W by the method according to the secondembodiment. The IPA thereby displaces the water-repellent agent.Furthermore, the water treatment apparatus 10 supplies the DIW again tothe semiconductor substrate W. The DIW thereby displaces the IPA.Thereafter, the water treatment apparatus 10 dries the semiconductorsubstrate W by spinning the semiconductor substrate W. At this time, thesemiconductor substrate W can be dried without collapsing of thepatterns on the semiconductor substrate W because the surfaces of thepatterns on the semiconductor substrate W are in a water repellentstate.

Third Embodiment

FIGS. 6A and 6B show an example of a configuration of a surfacetreatment apparatus 30 for semiconductor substrates according to a thirdembodiment. In the first and second embodiments, the surface treatmentapparatus 10 is a single-wafer surface treatment apparatus forprocessing semiconductor substrates W one by one. On the other hand, thesurface treatment apparatus 30 according to the third embodiment is abatch surface treatment apparatus for batch-processing a plurality ofsemiconductor substrates W. Therefore, the chamber 300 accommodates aplurality of semiconductor substrates W (semiconductor substrates Wcorresponding to two lots, for example) at a time. The interior of thechamber 300 can be kept in a vacuum when processing the semiconductorsubstrates W.

The chemical-liquid supply unit 220 sprays an evaporated organic solvent(IPA, for example) 3 into the chamber 300 so as to supply the organicsolvent 3 to the semiconductor substrates W. The organic solvent 3,which is evaporated, can spread through surfaces of the semiconductorsubstrates W. The spray unit 400 sprays the evaporated water-captureagent 2 into the chamber 300. The water-capture agent 2, which isevaporated similarly, can spread through the surfaces of thesemiconductor substrates W. Forms of the chemical-liquid supply unit 220and the spray unit 400 are not limited to specific ones, so that eithernozzle-like units shown in FIGS. 6A and 6B or the box-like units shownin FIG. 1 can be used as the chemical-liquid supply unit 220 and thespray unit 400.

For example, the IPA can be used as the organic solvent 3 similarly tothe organic solvent in the second embodiment. Any of the water-repellentagents can be used as the water-capture agent 2 similarly to thewater-capture agent 2 in the first embodiment.

A DIW reservoir 500 is a reservoir that stores therein the DIW and inwhich a batch of semiconductor substrates W can be immersed in the DIW.The DIW in the DIW reservoir 500 is circulated, filtered so as to keep alightly doped state after use, and reused.

FIG. 7 is a flowchart showing a surface treatment method according tothe third embodiment. The surface treatment method according to thethird embodiment is described with reference to FIGS. 6A, 6B, and 7.

First, the semiconductor substrates W are subjected to the cleaningtreatment using the cleaning liquid (S22). The cleaning treatment can beperformed either outside or inside of the chamber 300. In the thirdembodiment, it is assumed that the semiconductor substrates W arecleaned outside of the chamber 300 and that the semiconductor substratesW are arranged in the chamber 300 after the cleaning liquid is rinsedaway with the DIW.

The cleaning treatment can be performed either on every semiconductorsubstrate W or collectively on a plurality of semiconductor substrates Was a batch process. When the cleaning treatment is performed as thebatch process, it suffices to store the cleaning liquid in a reservoir(not shown) similar to the DIW reservoir 500 and to immerse thesemiconductor substrates W in the reservoir. A case of performing thecleaning treatment inside of the chamber 300 is described later in amodification of the third embodiment.

As described above, after the cleaning treatment, the cleaning liquid onthe semiconductor substrates W is rinsed away with the DIW (S32). Asshown in FIG. 6A, the semiconductor substrates W are introduced into thechamber 300 in a vacuum, the semiconductor substrates W are immersed inthe DIW reservoir 500, and surfaces of the semiconductor substrates Ware rinsed with the DIW (S42). Before or after arranging thesemiconductor substrates W in the chamber 300, the spray unit 400evaporates the water-capture agent 2 and sprays the evaporatedwater-capture agent 2 into the chamber 300. The water-capture agent 2thereby captures the water in the atmosphere in the chamber 300 (S52).

Simultaneously with or after spraying of the water-capture agent 2, thechemical-liquid supply unit 220 supplies the evaporated organic solvent3 to the surfaces of the semiconductor substrates W (S62). The organicsolvent 3 can easily spread through the surfaces of the semiconductorsubstrates W because the organic solvent 3 is sprayed in an evaporatedstate. At this time, the organic solvent 3 can spread throughout thesurfaces of the semiconductor substrates W without absorbing the waterbecause the water is hardly present in the chamber 300. The organicsolvent (IPA, for example) 3 can thereby easily displace the water onthe entire surfaces of the semiconductor substrates W when thechemical-liquid supply unit 220 supplies the organic solvent 3.

Next, the semiconductor substrates W are pulled out of the DIW reservoir500 and dried (S72). At this time, the organic solvent 3 displaces thewater on the surfaces of the hard masks HM. Therefore, it is easy toremove the DIW from the semiconductor substrates W and it is difficultfor the patterns of the hard masks HM to collapse. It is also possibleto suppress watermarks from being formed on the surfaces of thesemiconductor substrates W.

Other processes in the third embodiment can be performed similarly tothe corresponding processes in the second embodiment. According to thethird embodiment, it is thereby possible to perform the IPA dryingtreatment collectively on a batch of the semiconductor substrates W. Thethird embodiment can achieve effects identical to those of the secondembodiment.

Modification of Third Embodiment

In the third embodiment, the cleaning treatment for cleaning thesemiconductor substrates W (S22 in FIG. 7) and the DIW rinse treatmentfor rinsing away the cleaning liquid with the DIW (S32 in FIG. 7) areperformed outside of the chamber 300. In the modification of the thirdembodiment, the cleaning treatment for cleaning the semiconductorsubstrates W and the rinse treatment for rinsing away the cleaningliquid with the DIW are performed inside of the chamber 300. In thiscase, it suffices to initially store the cleaning liquid in thetreatment reservoir 500 and to replace the cleaning liquid in thetreatment reservoir 500 with the DIW after performing the cleaningtreatment. At this time, the semiconductor substrates W can be keptstored in the treatment reservoir 500. Alternatively, the semiconductorsubstrates W can be temporarily pulled out of the treatment reservoir500 and, after replacing the cleaning liquid in the treatment reservoir500 with the DIW, the semiconductor substrates W can be stored again inthe treatment reservoir 500 and the cleaning liquid on the semiconductorsubstrates W can be rinsed with the DIW.

After rinsing the cleaning liquid with the DIW, the semiconductorsubstrates W are pulled out of the treatment reservoir 500, and StepsS42 to S72 shown in FIG. 7 are performed. According to thismodification, the cleaning treatment and the drying treatment can beperformed for every batch of the semiconductor substrates W. Thismodification can also achieve effects identical to those of the thirdembodiment.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel methods and systems describedherein may be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the methods andsystems described herein may be made without departing from the spiritof the inventions. The accompanying claims and their equivalents areintended to cover such forms or modifications as would fall within thescope and spirit of the inventions.

1. A semiconductor manufacturing apparatus comprising: a chamber; achemical-agent supply part supplying a water-repellent agent or anorganic solvent to a surface of a semiconductor substrate having beencleaned with a cleaning liquid in the chamber; and a spray part sprayinga water-capture agent capturing water into an atmosphere in the chamber.2. The apparatus of claim 1, wherein the water-capture agent is made ofa material same as a material of the water-repellent agent.
 3. Theapparatus of claim 1, wherein the water-repellent agent is a silanecoupling agent, and the organic solvent is isopropyl alcohol.
 4. Theapparatus of claim 2, wherein the water-repellent agent is a silanecoupling agent, and the organic solvent is isopropyl alcohol.
 5. Theapparatus of claim 1, wherein the spray part sprays the water-captureagent into the atmosphere in the chamber either simultaneously with orbefore a timing at which the chemical-liquid supply part supplies thewater-repellent agent or the organic solvent to the surface of thesemiconductor substrate.
 6. The apparatus of claim 1, wherein thechemical-agent supply part sprays the organic solvent to the surface ofthe semiconductor substrate.
 7. The apparatus of claim 1, wherein thechamber accommodates a plurality of the semiconductor substrates, andthe chemical-agent supply part sprays the organic solvent to surfaces ofthe semiconductor substrates.
 8. The apparatus of claim 1, wherein thespray part is formed integrally with the chemical-agent supply part. 9.The apparatus of claim 1, further comprising a mounting part mountingthe semiconductor substrate in the chamber, wherein the mounting partrotates the semiconductor substrate in order to drain off a liquid onthe semiconductor substrate.
 10. The apparatus of claim 1, comprising avacuum device evacuating air from interior of the chamber.
 11. Amanufacturing method of a semiconductor device for manufacturing thesemiconductor device using a semiconductor manufacturing apparatus,which comprises a chamber, a chemical-agent supply part supplying awater-repellent agent or an organic solvent into the chamber, and aspray part spraying a water-capture agent capturing water into thechamber, the method comprising: arranging a semiconductor substratehaving been cleaned with a cleaning liquid in the chamber; spraying thewater-capture agent capturing water into an atmosphere in the chamber;and supplying the water-repellent agent or the organic solvent to asurface of the semiconductor substrate either simultaneously with orafter spraying of the water-capture agent.
 12. The method of claim 11,wherein the water-capture agent is a chemical liquid same as thewater-repellent agent.
 13. The method of claim 11, wherein thewater-repellent agent is a silane coupling agent, and the organicsolvent is isopropyl alcohol.
 14. The method of claim 12, wherein thewater-repellent agent is a silane coupling agent, and the organicsolvent is isopropyl alcohol.
 15. The method of claim 11, furthercomprising rinsing the surface of the semiconductor substrate withdeionized water after supplying the water-repellent agent.
 16. Themethod of claim 11, further comprising rotating the semiconductorsubstrate in order to drain off a liquid on the semiconductor substrateafter supplying the water-repellent agent or the organic solvent. 17.The method of claim 11, wherein supply of the organic solvent isperformed by allowing the chemical-agent supply part to spray thewater-repellent agent or the organic solvent to the surface of thesemiconductor substrate.
 18. The method of claim 11, wherein the chamberaccommodates a plurality of the semiconductor substrates, and thechemical-agent supply part sprays the organic solvent to surfaces of thesemiconductor substrates.
 19. The method of claim 15, wherein thechamber accommodates a plurality of the semiconductor substrates, andthe chemical-agent supply part sprays the organic solvent to surfaces ofthe semiconductor substrates.